Growth differentiation factor 8 (GDF8) or myostatin belongs to the transforming growth factor beta superfamily that controls anterior-posterior patterning during development by regulating the expression of Hox genes. GDF8 is a negative regulator of muscle growth, and has been shown to play a role in the regulation of cardiacmyocite proliferation.
GDF8 is closely related to GDF11, which is a negative regulator of muscle growth. Like GDF8, GDF11 is involved in the regulation of cardiacmyocyte proliferation. The similarities between myostatin and GDF11 imply a likelihood that the same regulatory mechanisms are used to control tissue size during both muscular and neural development. Mechanistically, the actions of myostatin are likely regulated by WFIKKN2, a large extracellular multidomain protein consisting of follistatin, immunoglobulin, protease inhibitor, and NTR domains. WFIKKN2 has been found to inhibit the biological activities of myostatin and has a high affinity for GDF11.
Both GDF8 (myostatin) and GDF11 play important roles in the course of development, and in the regulation of cell growth and differentiation in adult tissues. The ability to localize and/or measure these two proteins is important to further understand and distinguish their contributions in development and adult tissues (e.g., cardiac and skeletal muscle). However, due to their homology it is difficult to distinguish the presence and/or levels of these proteins with current protein binding reagents (e.g., antibodies). Thus, there is a need for protein binding reagents that are capable of distinguishing the GDF8 and GDF11. The present disclosure meets such needs by providing aptamers having binding specificity to a GDF8 protein.